Blowpipe



Jan. 25, 1949. w. J. JACOBSSON BLOWPIPE Filed Sept. 15, 1944 I il\\\\M EWWNA INVENTOR WILGOT J. JACOBSSON ATTORNEY Patented Jan. 25, 1949 nnowmrn Wilgot J. Jacobsaon, Piainfleld, N. .I., mama:- to

Union Carbide and Carbon Corporation, a corporaiion of New York Application September 15, 1944, Serial No. 554,190

7 Claims.

This invention relates to blowpipes, and more particularly to blowpipes including an elongated mixer or injector nozzle for one gas, the front end of which nozzle is critically spaced from the rear end of a mixer tube to provide an annular inlet for another gas.

In such blowpipes the elongated or extended mixer nozzle is subject to undesirable axial expansion due to heating, especially that caused by popping or backflring, which causes a reduction in the annular gas inlet space, with a corresponding decrease in the gas flowing through such space to the mixing chamber. This reduction in some cases even goes so far as to completely close such space, causing one gas to be entirely shut oil, and rendering the blowpipe inoperative.

The main object of this invention is to overcome such trouble by the provision of novel gastight bearing means for the rear end portion of the mixer nozzle, and resilient means urging such nozzle forwardly, so that the nozzle is free to expand or contract longitudinally without changing the critical gas inlet space at the front end thereof. Another object of the invention is to provide an improved blowpipe in which a combustible gas and a combustion-supporting gas are eiiiciently and effectively mixed regardless of changes in the length of cooperating mixer parts with respect to one another due to expansion or contraction.

In accordance with the invention, there is pro vided an elongated mixer nozzle with front end lugs which are adapted to engage and space the nozzle from the annular surface at the rear end of a mixer tube to provide an inlet for one of the gases, such lugs being held in constant contact with such surface by a spring, the force of which is transmitted through the nozzle. A gas-tight seal is provided at the rear end of the mixer nozzle. Such seal includes a spring loaded plastic hearing so that the nozzle is free to expand and contract longitudinally without affecting the critical gas inlet space at the front end of the nozzle.

Referring to the drawing:

Fig. 1 is a fragmentary view partlyin side elevation and partly in longitudinal cross-section of a deseaming blowpipe exemplifying the invention, and

Fig. 2 is an enlarged fragmentary sectional view taken on line 2-2 of Fig. 1.

The blowpipe B includes a valve body il, a tubular shell i2, a head and a nozzle, the latter two elements being omitted from the drawing. The valve body II is provided with an inlet i4 for one gas, in this case oxygen, and a separate inlet It for another gas, in this case acetylene. The gas inlets i4 and ii are connected to suitable sources of oxygen and acetylene by conventional means including hose nipples i8 and 2! which are threaded into the inlets i4 and i6, respectively.

The valve body it is also provided with a socket 22 in which is-threaded a plug 24 containing a cutting or deseaming oxygen valve having a stem 26 which is connected to one end of an operating lever 28. The lever 28 is pivoted to the valve body it at 3|! and includes a handle 32 which overlaps the shell I2 so that the shell may be gripped in one hand and the handle 32 operated with the thumb of such hand. When the cutting or deseaming oxygen valve is open, the oxygen inlet i4 is placed in communication with an oxygen passage 34 in the valve body ill, such passage 34 being connected to the blowpipe head and nozzle by means including a cutting oxygen pipe 36, the rear end portion of which extends through the shell B.

The valve body i0 is provided with axially aligned front and rear sockets 38 and 40 which are connected by a hole 4i. The rear end portion of a preheating oxygen pipe 42 is secured in the socket 38, the pipe 42 extending through the shell l2 in substantially parallel relation to the cutting oxygen pipe 36. Disposed within the pipe 42 and at a substantial axial distance away from the rear end of such pipe is a preheat-gas mixing tube 44 having a central gas mixing passage or chamber 46. The rear face of the mixing tube 44 constitutes an annular abutment 48 for annularly spaced lugs 50 on the front end of an elongated injector or mixer nozzle 52 which projects centrally into the pipe 42 through the hole 4| of the valve body Ill. The elongated nozzle 52 is supported in spaced concentric relation with the pipe 42 by annularly spaced tongues 54 around the forward end portion of the nozzle 52 and by the internal wall of the hole 4i at the rear end portion, the annular surface of the hole 4i providing a bearing for the nozzle as the latter expands or contracts axially.

An elongated annular passage 55 is thus provided between pipe 42 and the nozzle 52 for one of the gases, in this case oxygen, the latter being conducted to the passage 55 from the inlet l4 through a suitable cross passage (not shown) in the valve body ll. Thus, preheating oxygen flows through the annular passage 55 and between the ribs 54 to critical gas inlet space 56 between the front end of the nozzle 52 and the annular abut- I I claim:

ment .4. at the rear end of the mixing tube ll. At its forward end the nozzle I2 is provided with an insert 58 which is adapted to discharge the acetylene in a fine stream axially into the gas mixing passage or chamber 4'. At the same time preheating oxygen flows inwardly toward the acetylene stream through the critical annular-space 8'. a

The rear socket ll in the gas inlet body III is threaded to receive a screw it of a closure 62. Seated on the inner end or the screw is a disk 64 having a central stud 6 for internally supporting one end of a compression spring Cl, the inner end of which engages-the rear end of the elongated nozzle 52. The latter is internally threaded at 88 to be engaged by a removing screw (not shown). The spring is urges the nozzle 52 axially forwardly so that the lugs'ill are in constant contact with the abutment 48. leakage between the passage 55 and the socket 40, which is connected to the acetylene inlet i8 .by a cross passage (not shown) in the valve body III, is prevented by a spring loaded packing assembly, including a metal washer I0 seated in .the bottom of socket 40, a pair of plastic rings 12,

a metal sleeve 14, and a compression spring-i6 which is disposed between the metal sleeve and affecting the gas-tight seal. between the nozzle and the valve body ill.

The valve body it may be provided with conventional valves (not shown) for controlling the flow of oxygen and acetylene to the annular passage 55 between the pipes 42 and 52, and to the socket 40,. respectively. The blowpipe B is operated in a conventional manner when connected to suitable sources of oxygen and acetylene, the preheating gas mixture being delivered to the nozzle from the mixing chamber 45, and the supply of cutting of deseaming oxygen being controlled by manipulating the handle 32 in the usual operation of the blowpipe. However, backfire or popping which causes the elongated nozzle 52 to increase in length due to expansion, does not affect the critical clearance between the front of the nozzle and the corresponding annular surface of the abutment ill, because the rear end portion of the nozzle 52 is free to float or move with respect to the valve body it, thecompression springs Stand 78 maintaining the parts in proper position.

means disposed between the rear end portions of said pipe and nozzle, the rear end portion of said nozzle being free to expand and contract longitudinally insaid gas-tight bearing means,

and resilient means urging said nozzle forwardly within said pipe.

2. A blowpipe comprising, in combination, an elongated pipe containing a gas mixer having an annular surface, an elongated mixer nozzle subject to undesirable longitudinal expansion and contraction due totemperature changes and dis- .posed in spaced concentric relation within said .pipe for discharging astream of gas axially into said gas mixer, means disposed adiacentthe front end of said' nozzle for spacing the front end of said nozzle from the annular surface of said gas mixer to provide a gas inlet space to said mixer, means for supplying combustion-supporting gas to .an annular passage between said nozzle and pipe, means for supplying combustible gas to said nozzle, and gas-tight means disposed between the rear end portions of said pipe and nozzle, the rear end portion of said nozzle being free to expand and contract longitudinally in said gas-' tight means.

' 3. A blowpipe comprising, in combination, an elongated pipe containing a mixing tube having an annular rear end, an elongated mixer nozzle subject to undesirable longitudinal expansion and While the invention has been exemplified in connection with a medium-pressure mixer, i. e., one in which the acetylene or other fuel gas is axially discharged into the center of the mixing chamber and the combustion supporting gas is annularly discharged inwardly toward the fuel gas, the invention is equally applicable to lowpressure mixers, i. e., those in which the combustion supporting gas is axially discharged into the center of the mixingchamber and the acety;

contraction due to temperature changes and disposed in spaced concentric relation within said in said gas-tight means, and spring means urging said nozzle forwardly within said pipe.

4. In a blowpipe, the combination with a valve body having axially aligned front and rear sockets and a connecting hole, a pipe having one end portion secured in said front socket, an annular abutment in said pipe, an elongated mixer nozzle lene or other fuel gas is annularly discharg'edin wardly toward the combustion supporting gas as it enters the mixing chamber. The invention is also applicable to high-pressure" mixers.

1. A blowpipe comprising, in combination, an elongated pipe containing a gas mixing tube, an elongated mixer nozzle subject to undesirable longitudinal expansion and contraction due to temperature changes and disposed in spaced conin said pipe, means acting to space the forward end of 'the nozzle from said abutment, means acting to space said pipe and nozzle so that they' abutment in said pipe, an elongated mixer nozzle in said pipe having means engaging said abutment to space the forward end of the nozzle from said abutment, said nozzle also having means engaging said pipe so that the nozzle and pipe are concentric with an annular gas passage therebetween, said hole providinga bearing for the rear end portion of said nozzle, a closure for said rear socket, a disc seated on said closure, said disc having a central stud facing said nozzle, a compression spring disposed between said disc and the rear end of said nozzle for urging said nozzle forwardly against said abutment, the rear end of said spring surrounding said stud, and means providing a gas-tight seal between said valve body and said nozzle.

6. In a blowpipe, the combination with a valve body having axially aligned front and rear sockets and a connecting hole, a pipe having one end portion secured in said front socket, an annular abutment in said pipe, an elongated mixer nozzle in said pipe and having means engaging said abutment to space the forward end of the nozzle from said abutment, said nozzle also having means engaging said pipe so that the nozzle and pipe are concentric with an annular gas passage therebetween, said hole providing a bearing for the rear end portion of said nozzle, a closure member and the inner wall of the socket, a sleeve 7 7. In a blowpipe, a body having a socket provided with a gas inlet and a smooth hole of reduced diameter disposed in front of said socket,

tubular member, urging said tubular member" forwardly in position, the rear end of said spring surrounding said stud, and a gas-tight packing in said socket for said tubular member comprising a washer surrounding said tubular member in said socket, a packing ring between said tubular on the rear end of the tubular member, and a compression spring disposed between said sleeve threaded in said rear socket, a disc seated on sleeve adjacent the rear end of the nozzle, and

a compression spring disposed between said sleeve and said disc and surrounding said first-named spring.

and said disc and surrounding said first-named spring.

' s -WILGOT J. JACOBSSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Switzerland May 16, 1927 

